HST Calibration Reference Data System (CRDS)

 

NOTICE

The term "operational" has changed to "latest" when referring to the newest CRDS Context available. For more information, please refer to the user guide.

Documentation updates are ongoing. If something in the user guide is ambiguous, please reach out to the CRDS team or file a help desk ticket.


 

Obtain Best Reference Files

  1. Using the Command Line
  2. From Dataset ID or FITS Header Upload
  3. Exploring with Instrument Parameters

Reference File Database Services

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  3. Recent Activity

Latest References (under context hst_1333.pmap)

acs

hst_acs_0571.imap      Toggle N/A


atodtab ---- Analog To Digital Lookup Table

biasfile ---- Bias Frame

bpixtab ---- Data Quality (Bad Pixel) Initialization Table

ccdtab ---- Ccd Parameters Table

cfltfile ---- Coronagraphic Spot Flat Image

crrejtab ---- Cosmic Ray Rejection Parameter Table

d2imfile ---- Column Correction File

darkfile ---- Dark Frame

dgeofile ---- Geometric Distortion Correction File

drkcfile ---- Cte Corrected Dark

flshfile ---- Post-flash Image

idctab ---- Image Distortion Correction File

imphttab ---- Photometry Keyword Table

mdriztab ---- Multidrizzle Parameter Table

mlintab ---- Mama Linearity Table

npolfile ---- Non-polynomial Offset

oscntab ---- Overscan Region Table

pctetab ---- Pixel CTE Correction Table

pfltfile ---- Pixel To Pixel Flat Field Image

satufile ---- Full-Well Saturation Level Map

shadfile ---- Shutter Shading Correction Image

snkcfile ---- Sink Pixel Correction Image

spottab ---- Spot Position Table

cos

hst_cos_0377.imap      Toggle N/A


badttab ---- Bad Time Interval Table

bpixtab ---- Data Quality (Bad Pixel) Initialization Table

brftab ---- Baseline Reference Frame Table

brsttab ---- Burst Parameters Table

deadtab ---- Deadtime Reference Table

dgeofile ---- Geometric Distortion Correction File

disptab ---- Dispersion Relation Table

flatfile ---- Flat Field

fluxtab ---- Sensitivity Reference Files

geofile ---- Geometric Distortion Correction

gsagtab ---- Gain Sag Reference Table

hvdstab ---- Reference file that contains the slopes, y intercepts, and zero points of a high voltage-dependent sensitivity correction for COS FUV

hvtab ---- High Voltage Reference Table

lamptab ---- Template Calibration Lamp Spectra Table

phatab ---- Pulse Height Parameters Table

proftab ---- 2D Spectrum Profile Table

spottab ---- Spot Position Table

spwcstab ---- Spectroscopic WCS Parameters Table

tdstab ---- Time Dependent Sensitivity Table

tracetab ---- 1D Spectral Trace Table

twozxtab ---- Two-Zone Spectral Extraction Parameters Table

wcptab ---- Wavecal Parameters Reference Table

xtractab ---- 1-d Extraction Parameters Table

xwlkfile ---- X Walk Correction Lookup Reference Image

ywlkfile ---- Y Walk Correction Lookup Reference Image

nicmos

hst_nicmos_0250.imap      Toggle N/A


darkfile ---- Dark Frame

flatfile ---- Flat Field

idctab ---- Image Distortion Correction File

illmfile ---- Illumination Pattern File

maskfile ---- Static Mask File

nlinfile ---- Detector Linearity Correction File

noisfile ---- Detector Read-noise File

pedsbtab ---- pedsbtab

phottab ---- Phototmetric Calibration Table

pmodfile ---- Persistence Model Files

pmskfile ---- Persistence Mask Files

rnlcortb ---- Nonlinearity Power Law Table

saacntab ---- SAACLEAN Task Parameters

saadfile ---- Post Saa Dark Assoc.

tdffile ---- Temperature Dependent Flat Fields

tempfile ---- Temperature-dependent Dark Reference File

zprattab ---- Nonlincor Zeropoint Scaling Table

stis

hst_stis_0398.imap      Toggle N/A


apdestab ---- Aperture Description Table

apertab ---- Aperture Throughput Table

biasfile ---- Bias Frame

bpixtab ---- Data Quality (Bad Pixel) Initialization Table

ccdtab ---- Ccd Parameters Table

cdstab ---- Cross-disperser Scattering Table

crrejtab ---- Cosmic Ray Rejection Parameter Table

darkfile ---- Dark Frame

disptab ---- Dispersion Relation Table

echsctab ---- Echelle Scattering Table

exstab ---- Echelle Cross-Dispersion Scattering Table

gactab ---- Grating-Aperture Correction Table

halotab ---- Detector Halo Table

idctab ---- Image Distortion Correction File

imphttab ---- Photometry Keyword Table

inangtab ---- Incidence Angle Correction Table

lamptab ---- Template Calibration Lamp Spectra Table

lfltfile ---- Low-order Flat Field Image

mlintab ---- Mama Linearity Table

mofftab ---- Mama Offset Correction Table

pctab ---- Photometric Correction Table

pfltfile ---- Pixel To Pixel Flat Field Image

phottab ---- Phototmetric Calibration Table

riptab ---- Echelle Ripple Table

sdctab ---- 2-d Spectrum Distortion Corrections

sptrctab ---- 1-d Spectrum Trace Table

srwtab ---- Scattering Reference Wavelength Table

tdctab ---- Nuv Dark Correction Table

tdstab ---- Time Dependent Sensitivity Table

teltab ---- Telescope Point Spread Function Table

wcptab ---- Wavecal Parameters Reference Table

xtractab ---- 1-d Extraction Parameters Table

synphot

hst_synphot_0082.imap      Toggle N/A


obsmodes ---- Observing Modes Table

thermal ---- Component Thermal Tables

thruput ---- Component Throughput Tables

tmctab ---- Master Component Lookup Table

tmgtab ---- Graph Table

tmttab ---- Thermal Component Lookup Table

wfc3

hst_wfc3_0654.imap      Toggle N/A


atodtab ---- Analog To Digital Lookup Table

biacfile ---- CTE Bias Frame

biasfile ---- Bias Frame

bpixtab ---- Data Quality (Bad Pixel) Initialization Table

ccdtab ---- Ccd Parameters Table

crrejtab ---- Cosmic Ray Rejection Parameter Table

d2imfile ---- Column Correction File

darkfile ---- Dark Frame

dfltfile ---- Delta Flat Field Image

drkcfile ---- Cte Corrected Dark

flshfile ---- Post-flash Image

idctab ---- Image Distortion Correction File

imphttab ---- Photometry Keyword Table

mdriztab ---- Multidrizzle Parameter Table

nlinfile ---- Detector Linearity Correction File

npolfile ---- Non-polynomial Offset

oscntab ---- Overscan Region Table

pctetab ---- Pixel CTE Correction Table

pfltfile ---- Pixel To Pixel Flat Field Image

satufile ---- Full-Well Saturation Level Map

snkcfile ---- Sink Pixel Correction Image

wfpc2

hst_wfpc2_0250.imap      Toggle N/A


atodfile ---- Analog To Digital Converter Lookup Table

biasfile ---- Bias Frame

darkfile ---- Dark Frame

dgeofile ---- Geometric Distortion Correction File

flatfile ---- Flat Field

idctab ---- Image Distortion Correction File

maskfile ---- Static Mask File

offtab ---- Inter-chip Offsets Table

shadfile ---- Shutter Shading Correction Image

wf4tfile ---- WF4 Correction Table


Context History (more history, all contexts, build contexts)

Start Date Context Status Description
2026-05-14 hst_1333.pmap latest The STIS team is delivering reference files corresponding to the fifth flux recalibration release. These include updated throughput files using CALSPECv11 models, new traces for secondary echelle modes, and new background regions for echelle orders at the detector edges. File types being delivered are PHOTTAB, SPTRCTAB, RIPTAB, and XTRACTAB.
2026-05-13 hst_1332.pmap archived The WFC3 UVIS full-frame and subarray superbias, bia, files will affect all 1x1 binned UVIS data, and the WFC3 UVIS 2x2 and 3x3 binned superbias, bia, files will affect all 2x2 and 3x3 binned UVIS data taken from January 1 - December 31 2025. Currently, the automated calibration pipeline and Calibration Reference Data System include WFC3 UVIS full-frame, subarray, and binned superbias reference files only up to a USEAFTER date of January 1, 2024. With this delivery, the pipeline should use these reference files to perform bias subtraction on any 1x1, 2x2 or 3x3 binned UVIS datasets obtained between the dates above because they represent the most accurate estimate of the residual bias level at the time of the science observation. The 2025 WFC3 UVIS superbias files were generated using bias exposures from the HST Cycle 32 and 33 monitoring programs 17665 and 17944. More information regarding the method used to create UVIS superbias calibration reference files can be found in WFC3 ISR 2023 03. Additionally, the header of each reference file has a history section listing the datasets used to create each file. These new WFC3 UVIS post-flash files will apply to all UVIS images with medium or low flash current taken since January 1, 2025. They were created using the methodology detailed in WFC3 ISR 2023-01, using data from HST CAL programs 17671 and 17950. The delivery includes reference files for both shutters, A and B, and for both low and medium current.
2026-05-12 hst_1330.pmap archived These WFC3 UVIS superdarks will affect all UVIS data taken from April 3, 2026 to April 25, 2026. Currently, the automated calibration pipeline and CRDS have only WFC3 UVIS drk and dkc reference files with USEAFTER dates of up to March 30, 2026. The automated pipeline should now use these reference files to perform dark subtraction on any UVIS datasets obtained between the dates above, as they represent the most accurate picture of dark current and hot pixels for this time period. This new bad pixel table with USEAFTER of April 3, 2026 was generated using data taken from April 3, 2026, through April 28, 2026. Currently, the Calibration Reference Data System only has WFC3 UVIS bad pixel reference tables up to a USEAFTER date of March 2, 2026. The automated pipeline should now use this reference file as the bad pixel table on any UVIS datasets obtained from April 3, 2026 to present because it represents the most accurate measure of pixel stability at the time of the science observation. These WFC3 UVIS drk , dkc, and bpixtab files were generated using dark exposures from HST Cycle 33 CAL programs 17944 and 17947. More information regarding the method used to create the UVIS dark calibration reference files can be found in WFC3 ISR 2016-08. More information about the UVIS bad pixel tables is outlined in the WFC3 ISR 2018.15 and WFC3 ISR 2021.14. For more details regarding both deliveries, please see the Context History and select -all contexts- on the CRDS homepage.
2026-04-20 hst_1328.pmap archived Delivery of new STIS CCD bias and dark reference files for CCD data taken between March 17 2026 through April 16 2026. The files were generated from data taken in the same time frame under STIS calibration programs 18157 and 18155.